Refrigerant: What does it do?
A refrigerant is a fluid that flows in a closed path around the AC system:
• Depending on the temperature and pressure, the refrigerant cycles through a liquid and gas state
TECH TIP: The refrigerant oil cool can often provide us with some idea of the compressor and internal system. Black Oil indicates carbonization caused by air (moisture) in the system. Brown Oil indicates copper plating caused by moisture in the system. Grey or Metallic Oil indicates bearing wear or piston scoring. Piston scoring may be attributed to high head pressure caused by system moisture.